diff options
Diffstat (limited to 'arch/x86/kernel/tsc_sync.c')
| -rw-r--r-- | arch/x86/kernel/tsc_sync.c | 21 |
1 files changed, 16 insertions, 5 deletions
diff --git a/arch/x86/kernel/tsc_sync.c b/arch/x86/kernel/tsc_sync.c index 1d8508fd15f7..d0db011051a5 100644 --- a/arch/x86/kernel/tsc_sync.c +++ b/arch/x86/kernel/tsc_sync.c @@ -73,9 +73,11 @@ static void tsc_sanitize_first_cpu(struct tsc_adjust *cur, s64 bootval, * the TSC is in sync with the already running cpus. * * But we always force positive ADJUST values. Otherwise the TSC - * deadline timer creates an interrupt storm. Sigh! + * deadline timer creates an interrupt storm. We also have to + * prevent values > 0x7FFFFFFF as those wreckage the timer as well. */ - if ((bootcpu && bootval != 0) || (!bootcpu && bootval < 0)) { + if ((bootcpu && bootval != 0) || (!bootcpu && bootval < 0) || + (bootval > 0x7FFFFFFF)) { pr_warn(FW_BUG "TSC ADJUST: CPU%u: %lld force to 0\n", cpu, bootval); wrmsrl(MSR_IA32_TSC_ADJUST, 0); @@ -448,13 +450,22 @@ retry: * that the warp is not longer detectable when the observed warp * value is used. In the worst case the adjustment needs to go * through a 3rd run for fine tuning. - * - * But we must make sure that the value doesn't become negative - * otherwise TSC deadline timer will create an interrupt storm. */ cur->adjusted += cur_max_warp; + + /* + * TSC deadline timer stops working or creates an interrupt storm + * with adjust values < 0 and > x07ffffff. + * + * To allow adjust values > 0x7FFFFFFF we need to disable the + * deadline timer and use the local APIC timer, but that requires + * more intrusive changes and we do not have any useful information + * from Intel about the underlying HW wreckage yet. + */ if (cur->adjusted < 0) cur->adjusted = 0; + if (cur->adjusted > 0x7FFFFFFF) + cur->adjusted = 0x7FFFFFFF; pr_warn("TSC ADJUST compensate: CPU%u observed %lld warp. Adjust: %lld\n", cpu, cur_max_warp, cur->adjusted); |